AllPartsStore.com CFM Calculator: Choosing the right precleaner

CFM Calculator - How to choosing the correct CENTRI® Precleaner


	Cubic Inch Displacement (CID):	*
	Revolutions Per Minute (RPM):
	Volumetric Efficiency (charts below):	*
	Engine Type:
	Cubic Feet Per Minute (CFM):

*** To convert metric displacements to C.I.D. for use above, use the following conversion factors:
Displacement in Cubic Centimeters (cm3) x 0.06102 = C.I.D.
Displacement in Liters x 61.02 = C.I.D.

* Volumetric Efficiency Chart - 4 Cycle Engines**
Diesel	Naturally Aspirated	=	.85
	Turbocharged	=	1.60
	Turbocharged-Aftercooled	=	1.85
Gasoline	up to 2500 RPM	=	.80
	2500 to 3000 RPM	=	.75
	3000 to 4000 RPM	=	.70

* Volumetric Efficiency Chart - 2 Cycle Engines**
Diesel	Blower-Scavenged	=	1.40
	Turbocharged	=	1.90
	Turbocharged-Innercooled	=	2.10
Gasoline	up to 2500 RPM	=	.85
	2500 to 3000 RPM	=	.80
	3000 to 4000 RPM	=	.75


CENTRI® Precleaner numbers and the recommended CFM ranges
EX20	50 - 100	EX50	350 - 700
EX25	100 - 200	EX60	500 - 950
EX30	150 - 275	EX70	750 - 1350
EX40	200 - 400	EX80	950 - 1600

NOTE: For engines equipped with twin air intake pipes, divide the engine C.F.M. by two and apply the proper CENTRI® Precleaner to each of the pipes.